Do not create core image in seek(), when load() might not run

Author: radarhere

src/PIL/TiffImagePlugin.py

@@ -1195,7 +1195,7 @@ def seek(self, frame: int) -> None:
         # subsequent frames in the image. Image may be
         # different size/mode.
         Image._decompression_bomb_check(self.size)
-        self.im = Image.core.new(self.mode, self.size)
+        self._im = None
 
     def _seek(self, frame: int) -> None:
         self.fp = self._fp